Perhaps but what I'm saying is as standard you can set the fans to come on at a certain time so if it was not detrimental to also have the electric heater on then BMW would have given the function as it would be very useful. I suspect though that to get any decent heat the heater will need to be 250W if not more, which would draw 20A. On a cold day that would kill the battery pretty quickly so there is a good reason why BMW deny this functionality. You might be able to code it out but is there any point getting to a defrosted car that won't start?